Hydrogen is used at a few labs to launch small projectiles into media to simulate meteor strikes.
The hydrogen is not burned it is compressed with a piston driven by conventional propellants and recycled after each firing. They launch projectiles at hyper-sonic speeds. Called "Light gas guns" they are used at labs like Rice University and Arnold Air Force base.
The hydrogen is not burned it is compressed with a piston driven by conventional propellants and recycled after each firing. They launch projectiles at hyper-sonic speeds. Called "Light gas guns" they are used at labs like Rice University and Arnold Air Force base.